Process and apparatus for collating sheets



2 Sheets-Sheet 1 R. HEPP Dec. 22, 1964 PROCESS AND APPARATUS FORCOLLATING SHEETS Filed May 51, 1962 Rudolf Hepp INVENTOR Dec. 22, 1964R. HEPP PROCESS AND APPARATUS FOR COLLATING SHEETS 2 Sheets-Sheet 2Filed May 31, 1962 Rudolf Hepp IN VEN TOR.

Meda United States Patent Ofiice 3,162,434 Patented Dec. 22, 1964 9Claims. 61. 270-57) My present invention relates to a process andapparatus for the collating of flexible sheet material and, moreparticularly, for the stacking of printed sheets and the interpositionof inserts Within folded sheets.

In known apparatus of this type inserts are interposed between flaps offolded sheet material (e.g. newspapers, books, magazines and the like)by passing the folded sheet, which is held with its vertex downwardlyand its spread flaps open upwardly in a generally V-shaped configuration, while the insert is dropped between the flaps. In one typeof device the partially spread folded sheet is displaced continuouslyWhile the insert is moved toward and along with the sheet into placebetween its flaps, thus necessitating a complicated feeding and/ ortiming mechanism to insure that the insert will be properly positionedwithin the spread flaps. Another apparatus of this kind displaces thefolded sheet intermittently while the inserts are dropped between theflaps only during pauses in the forward motion. The latter arrangementgreatly reduces the rate at which such machine can operate.

It is an object of the present invention to provide a method ofinserting sheets between the flaps of a folded sheet continuously and ata rate substantially exceeding that of the hitherto existing devices ofthis character.

A further object of the invention is to provide an apparatus adapted toobviate the abovementioned disadvantages of the known systems whilepermitting the precise positioning of inserts between the flaps of afolded sheet.

Another object of the invention is to provide a simple and improvedmethod for stacking and collating sheet material.

These objects have been achieved, according to the invention by a methodwherein a folded sheet is continuously displaced past an insertingstation at which its flaps are spread to an angle of at leastsubstantially 90 and an insert, moving at the same velocity as thefolded sheet and in the same direction, is deposited on one of itsflaps. Advantageously, the process may be carried out with the aid of arapidly moving continuous conveyor upon which one flap of the foldedsheet lies substantially honzontally while the other flap is opened to avertical position. Operating at the same speed as the conveyor andjuxtaposed therewith, is a feeding device which deposits one or moreinserts upon the horizontal flap of the previously unfolded sheet. Thefeeding device may, according to a particular feature of the invention,comprise a roller rotating about a substantially horizontal axistransverse to the direction of displacement of the conveyor with aperipheral speed equal to that of the conveyor so that the insert isinvariably disposed in a predetermined position between the flaps of thefolded sheet.

A further feature of the invention resides in the provision of means,synchronized with the conveyor belt for depositing the folded sheetsthereon and opening them so that their flaps lie respectively in thesubstantially horizontal and vertical positions previously mentioned. Itshould be noted that it is not necessary that one of the flaps beprecisely vertical but only that the two flaps include an angle greaterthan about 90 so as to permit deposition of the insert on the horizontalflap without interference by the opened flap, i.e. the flap not in thehorizontal position. The unfolding means may, advantageously, comprise asuction device, adapted to draw apart the corners of the folded sheet,operating in conjunction with guide means for holding the spread flapsapart during the travel of the folded sheet past the inserting station.The suction means preferably c0mprises a pair of suction devicesjuxtaposed on opposite sides of the sheet and displaceable concurrentlywith the conveyor so that the travel of the sheet is not impeded.

At the inserting station I provide insert-supply means, which alsooperates synchronously with the conveyor belt, for feeding the insertsheets to the drum at a rate equal to the rate at which folded sheetspass the latter. The conveyor may be provided with abutments at spacedlocations therealong for positive entrainment of the folded sheets andthe inserts disposed therein. The abutments preferably project above theconveying table to a height in excess of the height of the stackedsheets to be disposed on the table. Thus, a plurality of insertingand/or stacking stations may be provided along the length of theconveyor to deposit substantially any uurnber of sheets thereon. At eachstacking station I provide a similar drum rotatable about a horizontalaxis transverse to the direction of displacement of the conveyor andparallel to the sheets for depositing, at the speed of the conveyor,sheets on top of the folded sheet carried thereon. At the stackingstations the spreading means may be dispensed with if it is desiredmerely to place a second sheet, which may or may not be folded, on topof the earlier deposited folded or nonfolded sheet. At the outgoing endof each of the inserting stations disposed along the conveyor I provideme-ans for guiding the open flap back into place overlying the newlyintroduced insert.

While the collating and stacking drums may be pro vided with suctiondevices for entraining the sheets to be deposited on the sheetspreviously placed upon the conveyor, I prefer to employ holding meanshaving a surface extending over an arc of the periphery of the drum andhugging the latter so that the sheets fed to the drum are pressedagainst it by the surface. This surface may advantageously, be formed bya moving band operating at the peripheral speed of the drum so as toeffect a clamping of each sheet between the band and the drum periphery.Since it may be desirable to feed a plurality of stacked inserts to eachdrum at any station, I prefer to employ a conveyor belt Whose surfaceextends generally parallel to the axis of the drum and to provide itwith abutments of the character previously described for entraining astack of inserts and feeding it between the drum and the band surfaceperipherally hugging the latter. A further drum, which may be rotatableabout an axis parallel to the surface of the feeding conveyor buttransverse to the axis of the collating drum, may be disposed above thefeeding conveyor to successively deposit sheets thereon to form thestack.

A further feature of the instant invention resides in the provision ofadjusting means along the conveyor to facilitate the accommodation ofthe latter to sheets of substantially any size so that a singleinstallation may serve for collating of any papers, magazines and bookswithout requiring major structural changes to accommodate the diiferentsheet widths characterizing them. Since it is frequently desirable toposition an insert accurately within a folded sheet and/or to dispose asuperimposed sheet upon an underlying sheet, I provide means forsynchronizing the motion of the conveyor belt and the drums so as topermit the latter to selectively deposit the sheets entrained therebyupon the conveyor at substantially any position relative to the sheetscarried thereby. Thus I provide means for varying theposivariable-clutch arrangement which is periodically actuated todeposit inserts shorter than the folded sheet alternately adjacenttheforward and rearward edges thereof so as to insure that the resultingbooklet or stack has a substantially uniform thickness. The variousstations along -the conveyor may be provided with interchangeablecomponents adapted to accommodate sheets of various widths.

The above and other objects, features and advantages of the presentinvention will be more readily apparent from the following description,reference being made to the accompanying drawing in which:

FIG. 1 is a schematic illustration of a prior-art method of collatingfolded sheets; V

FIG. 1A is a diagrammatic illustration showing the steps of collatingand in serting sheets according to the present invention;

FIG. 2is a side-elevational view of an apparatus for interposing insertsbetween the flaps of a folded sheet according to the invention;

FIG. 3 is a planview of the apparatus of FIG. 2;

FIG. 4 is an end view of the apparatus showing a detail thereof; I,

FIG. 5 is a side-elevational view of sheet-unfolding means employed inthe apparatus;

FIGS. 6 and 7 are views similar to FIG. 2 showing collatinginstallations according to further embodiments of the invention; and

FIG. 8 is a side-elevational View, parts broken away, of asheet-depositing station suitable for use in any of the installationsshown in FIGS. 2, 6 and 7.

In FIG. 1 of the drawing I show the conventional.

methodof introducing inserts into a folded sheet; According to thismethod, a folded sheet A is displaced either continuously orintermittently in the direction of arrow 100 with its flaps 101, 102slightly spread in a V-shaped configuration. As the folded sheet Apasses the inserting station 103 an insert B is placed edge wise betweenthe slightly spreadflaps 101, 102 of the upwardly open sheet A whencethe latter continues in the direction 100 and now is part of a booklet104.

In contradistinction to these hitherto known methods,

the folded sheet A is, according to the method of my present invention,spread so that its flaps 101, 102 include a minimum angle of 90, withone of the flaps lying in a substantially horizontal position, Whilebeing continuously displaced in the direction of arrow 1116. At

station 111, an unfolding station 117 (best shown in FIG. 5) at whichthe folded sheet A is spread to receive an insert and an insertingstation 118 at which the insert is placed between the flaps of theunfolded sheet. Referring now to FIGS. 24 it may be seen that theuprights 1 form a supply magazine at feeding station 111 for a feed drum119 which is journaled between a pair of supports 120, 121 for rotationabout a substantially.

horizontal axis parallel to the direction of displacement of the sheetsalong the conveyor 3 (arrow 1%). Drum 119 carries a plurality ofconventional suction rollers 2 which, as drum 119 rotatescounterclockwise as seen in FIG. 4, grip the folded sheets A of stack110 substantially at the fold line and swing them onto the table 116where they rest until engaged by the abutments 4 of chains 112, 113. Thesuction in rollers 2 is cut off just as the sheet A is deposited'uponthe table. In order to hold the sheet against the periphery of drum119the1atter may be provided with perforations and connected to a sourceof reduced pressure so that each sheet'A is held lightly thereagainstbut is able to fall from the drum under the action of gravity as thedrum begins its upward motion. Drum 119 isrotated on its shaft 122 bythe motor 7 whose pulley 123 drives a power-take-off shaftfi via adriven pulley 124 and a belt 125. Between the shaft 122 and thepower-take-oif shaft 6 I introduce a variable-speed transmission orclutch 5 (e.g. a friction or jaw clutch) which is coupled to the shaft122 of drum 119 via a pulley 126, a belt 127' and a further pulley 128.Chains 112 and 113 are also driven by motor 7 via a belt 129 which, fromshaft 6, rotates a bevel gear 139 journaled in an end wall 131 of thehousing 132 supporting table 116. This housing encloses the chains 112,113, the transmissions for the several stations, and the power-takeoifshaft 6. Thus, feed drum 119 is driven synchronously with chains 112,113 but at a speed determined by clutch 5 so that, for example, with thedrum 119 ro tating at a high speed relative to the rate of displacementan insertion station 167 an insert B,v extending substantially' parallelto and moving at the rate of displacement of sheet A, is depositedthereon so that the latter, eontinuing its displacement, reaches aposition 1118 Wherein its flaps may be closed or further sheets disposedtherebetween. If the flaps are closed, the resulting stackv may movecontinuously to a further station 109 wherein another sheet B, alsomoving with the speed of sheet A, may be superimposed thereon. Themethod according to. the invention may be continued to form a stack ofany size with or without interposition of inserts between the flaps offolded sheets. This will be more readily apparent from the descriptionbelow of various types of apparatuses for carrying out the method.

For example, in FIGS. 25 of the drawing, 1 show a stack 11% of foldedsheets A received between the uprights 1 of a feeding station 111disposed at one end of a continuous conveyor 3, The latter may be formedas a pair of transversely spaced parallel chains 112, 113 which passover a drive roller 114 and an idler roller 115 to displace the sheets.At spaced locations therealong, thechains 112, 113 are provided withabutments 4 which project above the plane of a substantially horizontalI table, 116 upon whiohthe sheets rest.

of; chains 112, 113, a plurality of sheets may be deposited upon thetable before each set of abutments 4 entrains the sheets along the tableto the stations spaced therealong.

Porwardly of the feeding station'111 along table 116 I provideunfoldingor spreading means for lifting the flap 1120f each sheet A into asubstantially vertical position or a position wherein this flap includeswith the horizontal flap 1691, resting on the table, an angle in excessof To this end the spreading means 117 shown in FIG. 5 comprises a pairof suction heads 8, 34 displaceable along the table at the rate of thesheets A. In the spreading means shown, the upper head 8 is connected toa link of the chain 11 whoselower pass is closely juxtaposed with theupper flap 102 of the sheet. Chain 10, disposed along the edge 133 ofthe sheets A opposite their folded, edge 134, passes over a pair ofsprocket wheels 11 journaled for rotation in a bracket 135 about ahorizontal axis transverse to the direction of displacement of conveyor3. Head 34 is carried by ,a further chain 35' which passes over a pairof sprocket wheels 36 disposed. below table 116, while the path of chain35 along table 116 lies,substantially parallel to this table. isprovided with a guide 12 which holds this chain parallel to the tableand thereabove only for a short length 16' sufficient to permit suctionhead 810 draw the upper flap 102 of a sheet thereagainst. The workingpath of chain 19 also includes an upwardly inclined portion 111" in thecourse of which this upper flap is raised to clear an unfolding tongue15 which is interposed between the flaps as the foldedsheet is disposedalong the table 116. ,A flexible tube 13 couples the upper head 6 with arotatable hollow suction conduit 1,4 which is rotated in step with thesprocket wheels 11 by a chain 136. A'sirnilar suction tube 137 is joinedwithia rotatable conduit 13.8. of the Chain 10 outwardly as the sheet Ais displaced along the table 116 and holds the sheet in the openposition. Head 119 may be cantilevered at the inserting station 118.Drums 119, 145, 219, 245 are of the type disclosed in application SerialNo. 828,476, filed July 21, 1959, now Patent No. 3,130,966.

To permit accommodation of folded sheets of various widths I provide anadjustable stop member 27 displace able on table 116 transversely to thedirection of displacement of the sheets therealong at the feedingstation 110 to position the sheets A with respect to the chains 112,113. Since it is advisable for at least the upper suction head 8 to bedisposed as close to the edge 133 of each sheet A remote from its foldline 134, I provide a screw 140, rotatable in a pillow block 141, whichthreadedly engages the bracket 135 for shifting the latter and its chaintransversely to the direction of displacement (arrow 116) of sheets A.

As the sheets A pass along the table 116 toward the inserting station118, guide 9 raises the upper flap 102 into a position wherein itincludes an angle of at least 90 with its horizontal flap 191 as shownat 142 in FIG. 2. In this condition the sheet is displaced past aninserting drum 22 which deposits the stack of insert sheets B thereon.The inserting station comprises a supporting housing 143 in which isjournaled a pair of rollers 21 of a gathering conveyor 19 whoseabutments 29 extend upwardly through a groove 144 of a gathering table18. Depending upon its speed of rotation, a drum 145, in all respectssimilar to drum 119 previously described, re moves individual insertsheets B from a stack 146 thereof. The sheets are then deposited upontable 18 until an abutment 212 of chain 19 engages the resulting packand displaces it into the gap 26 between the inserting drum 22 and aband 24 extending over a substantial portion of the periphery of thisdrum for holding the pack of inserts thereagainst. Band 24, which isdisplaceable at the peripheral speed of drum 22 along its supportingrollers 147, guides the insert pack in the direction of displacement ofthe sheets A for deposition upon their respective lower flaps 101. Aspreviously noted, the inserting drum 22 is operated with a peripheralspeed equal to the rate of displacement of chains 112, 113 so that thepack is dropped directly onto the folded sheet without relative motion.The drum 22 is driven by a chain 23 via a bevel gear transmission 148from a variable-speed transmission or adjustable clutch 17. The latteris provided with an indicator disk 9% from which the transmission ratioor position of adjustment may be read. The input gear 149 of the clutchis rotated by a gear 150 on the power-take-oif shaft 6. An outputsprocket 151 of clutch 17 is coupled via a belt 152 to the drivensprocket 153 of drum 14-5 whose shaft 154 is journaled between the upperrights 143' of base 143. A spring-loaded roller 25 bears upon chain 23to take up the slack of this chain and to prevent slowing down of drum22. Roller 25 and a a similar roller not shown may also be employed tosupport the chains 112, 113 of conveyor 3 at the point of insertion toinsure proper deposition of the insert pack on the folded sheet. As thesheet A carrying its pack of inserts B passes out of the insertingstation 118, the sheet-metal guide permits the upper flap 1G2 thereof tofall back over its lower flap and the inserts carried thereon.Replacement of the upper flap is facilitated by a plurality of blowers154, 155 spaced along the guide 9 to hold the flap 162. thereagainst. Afurther blower 156 is disposed above the table 116 forwardly of guide 9to fully close the folded sheet which then may travel to furtherinserting and/ or sheet-depositing stations as shown, for example, inFIGS. 6 and 7. So that the gathering table 18 of the inserting station113 may accommodate inserts of various widths, this table is providedwith a transversely shiftable stop 27', similar to the stop 27previously described. Each of these stops 27, 27' is provided with apair of links 157, 158, 157, 158' pivotally secured thereto and to therespective table 116, 18 to form a parallel-motion linkage whose contactsurface always remains parallel to the longitudinal edge of the foldedsheets A and the inserts B.

In FIG. 6 I show an arrangement generally similar to that previouslydisclosed wherein the feeding station 211 is disposed along the path ofa conveyor 203. Forwardly of the feeding station 211 along this path Iprovide a depositing station 266 and an inserting station 218. Thus,folded or unfolded sheets C may be fed from a magazine by a drum 219onto the table 216 whereupon the abutments 264 of the conveyor 203entrain the several sheets piled on the table and carry them to thedepositing station 216. The latter may deposit one or more folded sheetsD from its stack 246 on its collecting plate 246 via a drum 24-5. Fromplate 246 the stack of folded sheets D is fed between flexible band 224and the depositing drum 222 by a conveyor 219. The stack is thendeposited upon the uppermost sheet C of a pile thereof passingtherebelow. In all respects, the depositing station 269 is identicalwith the inserting station 118 previously described, but with theomission of the unfolding device 10 and guide 9 associated therewithinasmuch as the sheets deposited at station 260 are placed on top of thepile of sheets C.

Since the uppermost sheet of the pile leaving station 26%) is folded inthe manner of sheet A, an unfolding device 210 may be provided forwardlythereof along the table 216 to lift the upper flap of this topmost sheetwhence a guide 269 maintains it at right angles to its lower flap as thepile passes through the inserting station 218. The latter is, of course,identical to the station 118 previously described and deposits :1 packof inserts E between the fiaps of the topmost sheet of the pile.

In FIG. 7 I show a somewhat modified arrangement wherein a pile ofsheets F are deposited at a feeding station 311 upon the table 316 whilea conveyor 303 entrans them therealong. A first depositing station 360places a pack of sheets G upon the pile passing therethrough while stillanother depositing station 360' places a further stack of sheets Hthereon. Stations 360 and 369' are, of course, similar to station 2611described above.

It will be readily apparent that substantially any succession of theseveral stations described may be provided along a conveyor as required.Thus, the collating installation may be capable of interposing one ormore folded or nonfolded inserts between the folds of a sheet previouslydeposited upon the conveyor at a first inserting station 118 or 218 and,subsequently, disposing further insert packs between the folds at asuccessive station. Another package of sheets may then be superimposedupon the closed folded sheet containing the two sets of inserts at afurther station (265, 3613) while the topmost sheet of the resultingpile may, thereafter, be unfolded to permit the insertion of additionalpacks or similar sheets as desired. To employ the inserting apparatusfor superimposition of sheets upon a folded or nonfolded sheet displacedalong the conveyor, it is merely necessary to shut off the unfoldingdevices 10, 210 whereupon the sheets will remain folded as they passthrough the station so that the packs are superimposed thereon ratherthan inserted between its folds. When the unfolding devices 1b, 219 arecut off, the guides 9, 209 are rendered ineffective since the upper flapof a folded sheet is not lifted to engage the guide.

In FIG. 8 I show, somewhat schematically, an arrangement forperiodically varying the position at which inserts shorter than thesheets traveling upon the conveyor 3 are deposited in order to produce astack of substantially constant thickness. A magazine 23 contains .astack of sheets T adapted to be deposited upon piles 176 displacedtherebelo-w by a conveyor 3 Without movement of the sheets in mutuallyperpendicular directions as in the previously described devices 218,260,

7' thesheets are brought into engagement with admm 31 by a swingingsuctioniarm 29 of a conventional type. Drum 31 is partially embraced bya band 32- which is displaceable at the peripheral speed of this drumabout its horizontal axis 39 transverse to the direction of displacementof the piles 170. Each sheet T is then drawn between the band 32 and thedrum 31 into a position wherein it is engaged by a further drum 33 and asimilar band 171 for deposition upon the piles 170 in the mannerdescribed previously with reference to drum 22 and band 24. The suctionarm 29 is swung periodically by means of a clutch 172 coupling itwiththe power-takeoff shaft 6. Clutch 172. is periodically tripped by arotating cam 173' having angularly adjustable camming members 174, 175.Thus, upon rotation of cam 173 by its motor 176 which is coupled withshaft 6 and is, therefore, synchronized therewith, the camming members174, 175 operate the clutch 172 to feed successive sheets via drums 31and 33 onto the piles .170. The camming members 174, 175 may be sopositioned as to cause successive sheets to meet the leading andtrailing edges of successive piles 170 as shown in FIG. 8. A similararrangement for periodically operating the clutches 5, 17 may beprovided if it is desired to vary alternately the position of theinserts. A second arrangement (primed reference numerals) identical tothe one described is provided forwardly along the conveyor belt 3 sothat each pile receiving'an overlay sheet along its forward edgewillsubsequently receive another sheet along its rearward edge,

andvice versa. Each of the arrangements shown can be prewt by a suitableadjustment of the clutches 172, 172, with a consequent deactivation ofthe control members 173, 173', so that one of the inserting drums 33, 33deposits a respective insert along the leading or trailing edge of apile 170 while the other drum deposits its inserts along the other edge.Clutches 17 etc. may be similarly adjusted. Moreover, one of thearrangements shown in FIG. 8 can be employed together with the station118 shown in FIG. 2 so that both may deposit their respective sheetsbetween the folds of a sheet traveling upon the conveyor 3 or either onemay operate in the absence of operation of the other. It is alsopossible to provide means for periodically shifting the entire assembly18, 21, 22, 24in a direction transverse to the direction of displacementof the sheets along the table 116 and parallel to the latter foralternately depositing insertsralong the folded edge 134 and the remoteedge 133 of each sheet.

The invention described and illustrated is, as noted above, believed toadmit of many modifications and variations which will be readilyapparent to persons skilled in the art, all such modifications andvariations being deemedincluded within the spirit and scope of theinvention as claimed.

I claim: v 1. A method of collating sheets, comprising the steps ofdisplacing a plurality of sheets folded along a line in 1 line along atransport path lying in a substantially horizontal plane, said sheetseach having a lower flap and anupper flap" overlying said lower flap,raising said upper flap to a position in which it includes with saidlower flap an angle of at least substantially 90, depositingasecondsheet upon said lower flap of each of said first sheets by displacingsaid second sheet above said lower flap in said predetermined. directionat a speed equal to the speed of displacement of said. first sheetsWhile dropping it upon said lower flap, and folding said. upper flap ofeach of said first sheets over the second sheet disposed on itsrespectivelo-wer flap. V

V 3. A; method according to claim 2 wherein a stack of said secondsheets is disposed upon said lower flap at said inserting station.

4. A method according to claim 3 wherein said stack is formed by pilinga plurality of individual sheets prior to deposition of said stack uponsaid lower flap.

5. An installation for collating sheets, comprising substantiallyhorizontal conveyor means for displacing a plurality of sheets along acontinuous transport path, feed means for depositing a plurality ofsheets folded along a line upon said conveyor means with the fold lineof each of said sheets oriented in the direction of dis face approachingsaid conveyor means and moving in the direction of displacement thereofwhile being adapted to entrain an insert for disposing said insertbetween the flaps of a sheet passing therebelow, and means forwardly ofsaid inserting means for closing said flaps, said spreading meanscomprising suction means disposed above said transport path, a supportfor said suction means moveable along said transport path at the rate ofdisplacement of said sheets for raising a respective upper flap of atleast some of said sheets While said sheets are continuously displacedtherealong, and guide means forwardly of said suction means along saidtransport path for engaging the raised flaps of said sheets andretaining them in a raised condition wherein they include an angle inexcess of with a respective lower flap as said sheets pass saidinserting means, said support means comprising a moving endless bandcarrying said suction means, deflector means for said band forming apass thereof juxtaposed with said conveyor means diverging awayvfromsaid band in the direction of displacement of said sheets, andtransmission means coup-ling said conveyor means and said band forconcurrent operation.

6. An installation according to claim 5 wherein said "to the directionof displacement of said conveyor means and parallel to said sheets, andholding means cooperating with said drum for urging an insertthereagainst, further comprising common drive means for said conveyormeans and said drum whereby said drum is rotated with a peripheral speedequal to the rate of displacement of said conveyor means. a

7. An installation according to claim 6 wherein said holding meanscomprises a flexible band displaceable concurrently with said drum andhugging its periphery over a substantial portion thereof, said band andthe periphery of saiddrum forming an inlet remote from said conveyormeans and an outlet adjacent said conveying means, and stack-formingmeans adjacent said inlet for collecting a plurality of insert sheetsand feeding them through said inlet between said drum and said bandwhereby said stack is deposited upon a spread sheet passing below saiddrum.

8. An installation according to claim 7 wherein said stack-forming meanscomprises a table, a conveyor positionedbelow said table and formed withabutments extening therethrough, said abutrnents being spaced apart bydistances greater than the length of said insert sheets, and. feed-drummeans for stacking a plurality of said insert sheets upon said tablepiror to entrainment by one of said abutrnents of the stack thus formed.

9. An installation according to claim 5, further comprising periodicallyadjustable transmission means interconnecting said conveyor means andsaid inserting means for opertaion in timed relationship alternately todeposit said inserts along a leading edge and a trailing edge of each ofsaid sheets.

References Cited in the file of this patent UNITED STATES PATENTSHalvorsen Nov. 19, Tornberg Apr. 7, Kleineberg et al June 28, Volks etal. Oct. 23,

1. A METHOD OF COLLATING SHEETS, COMPRISING THE STEPS OF DISPLACING APLURALITY OF SHEETS FOLDED ALONG A LINE IN A PREDETERMINED DIRECTIONPARALLEL TO SAID LINE ALONG A TRANSPORT PATH, PARTIALLY UNFOLDING SAIDSHEETS, AND DEPOSITING A SECOND SHEET UPON EACH OF SAID FIRST SHEETS BY